Journal of Cell Science 116, e1105 (2003)
Copyright © 2003 The Company of Biologists Limited
AKAP149: anchor, integrator, regulator
A-kinase-anchoring proteins (AKAPs) facilitate compartmentalization and
integration of cell signalling by targeting molecules such as protein kinase A
and protein phosphatase (PP1) to specific subcellular locations. AKAP149, for
example, targets PP1 to the nuclear envelope (NE), where it is implicated in
control of NE reassembly after mitosis. Philippe Collas and co-workers have
examined AKAP149's role in this process in detail (see
p. 2237). They find that
AKAP149 not only targets PP1 to the NE but acts as a substrate specifier as
well: it enhances PP1 activity towards B-type nuclear lamins while inhibiting
dephosphorylation of other substrates, and this promotes assembly of lamins
into the NE. The authors also show that PP1 is associated with NE-bound
AKAP149 during G1 phase but released in S phase. Moreover, they demonstrate
that peptides that interfere with AKAP149–PP1 interactions trigger lamin
phosphorylation and depolymerization, which leads to G1 arrest and ultimately
apoptosis. Collas and co-workers therefore conclude that, by targeting PP1 to
the right place at the right time and ensuring it dephosphorylates the right
substrate, AKAP149 controls nuclear lamin assembly and maintains nuclear
envelope integrity during G1 phase.
Related articles in JCS:
- AKAP149 is a novel PP1 specifier required to maintain nuclear envelope integrity in G1 phase
- Rikke L. Steen, Monique Beullens, Helga B. Landsverk, Mathieu Bollen, and Philippe Collas
JCS 2003 116: 2237-2246.
[Abstract]
[Full Text]
